But all eyes were on Camp Nou. An early goal from Luis Suarez and an own-goal from Layvin Kurzawa were followed a Lionel Messi penalty soon after halftime had Barcelona 3-0 up on the day and just a goal behind on aggregate after 48 minutes. Edinson Cavani seemed to have settled it just after the hour, with his away goal meaning that Barcelona needed three goals to avoid elimination.

The game seemed to be drifting but Neymar thumped in a late free-kick and converted a last-minute penalty before setting up Sergi Roberto for a last-gasp winner that will be replayed for ages.

Here are three thoughts on one of the more remarkable days in Champions League history:

PSG panics, and Barcelona makes history

It shouldn’t have been possible. It shouldn’t have happened. Not until the 95th minute of the second leg did Barcelona have the lead in the series. Even up 5-1 in the second leg, Barcelona was still going out until Sergi Roberto slid in to force Neymar's pass over the line. The right back had an awful game in Paris, but history will regard it as just the prelude to his moment of crowning glory.

It was a game Barcelona had lost twice. It had lost in Paris when it collapsed to a 4-0 defeat. And then it had lost when Cavani slammed in an away goal to make it 3-1 on the night. Even with two minutes of the 90 remaining there seemed no chance of Barcelona going through.

The impossible comeback looked a lot less impossible after three minutes as Barcelona took the lead. Suarez reacted quicker than anybody else as PSG’s defense panicked under an awkwardly spinning ball and flicking a header over Kevin Trapp. That boded ill for PSG, but it reset and defended relatively well. Barcelona had chances, but they were largely speculative and from long range. On the odd occasion it did create half-chances, Rafinha’s crossing and an uncharacteristically poor touch from Suarez saw the opportunities wither.

But just as the momentum seemed to be going out of Barcelona, it struck again, six minutes before halftime. Again the goal was a strange mess, a combination of Parisian nervousness and a weirdly bouncing ball. Andres Iniesta chased a dinked ball over the defense, and when Marquinhos missed it, he forced across goal with a sharp downward back-heel. The ball looped up and Kurzawa thrashed wildly, the ball glancing off his knee and into the net. Barcelona, without having played especially well, suddenly found itself halfway there.

The momentum was with Barcelona and it was awarded a penalty four minutes into the second half as Thomas Meunier stumbled and tripped Neymar. Messi hammered in from the spot, and by then, any thought of holding what it had had left PSG. The game became unthinkably end-to-end. Meunier crossed for Cavani, who hit the post. And then, in the 62nd minute, Cavani smashed in a half-volley from Kurzawa’s knockdown, and with that the Camp Nou fell silent.

But Barcelona remained undeterred. Despite 26 minutes of slightly tepid football that followed, Neymar thumped in an 88th-minute free kick, and Barcelona believed again. Suarez collapsed under challenge from Marquinhos and was, perhaps fortuitously, awarded a penalty. Neymar converted. Suddenly Barcelona was hurling men forward. Goalkeeper Marc-Andre ter Stegen went up for a free kick. The ball was cleared, but the keeper won it back and was hacked down, drawing the foul that led to the series-winning sequence. Neymar played the free kick into the box and as PSG froze, Sergi Roberto squeezed in a wholly improbable winner.

Barcelona is alive and kicking, and PSG is left to rue what could have–and should have–been.

Away goals rule nearly spoils another series

When the away goals rule was introduced in 1965, it wasn’t fair, but it made a certain sense. Travel was difficult, conditions varied radically from country to country and home teams habitually made it difficult for away sides who responded by looking to spoil and waste time. The away goals rule encouraged away sides to attack. It makes no sense that you go through if you draw 1-1 away and 0-0 at home but out if you draw 0-0 away and 1-1 at home, but at least there was some logic to it.

But away wins are on the rise. Travel is easier. Conditions are more homogenous. Home teams are scrutinized for skulduggery. The laws have changed to make spoiling more difficult. The away-goals rule has become counterproductive. It should encourage open football, but actually it destroys games. With Barcelona 3-0 up, a goal behind on aggregate, and half an hour to play, the match was perfectly poised. Then Cavani scored and the game looked over. From needing one to pull level, Barcelona needed three not to lose. That it got them doesn’t change the insidious nature of the rule.

It makes no sense, no more than it would have done had Napoli won 2-0 against Real Madrid on Tuesday and gone through, or will do if Leicester beats Sevilla 1-0 or Monaco beats Manchester City 2-0 next week and progress.

After wasteful first leg, Aubameyang comes through

Having missed so many chances in Lisbon, Dortmund wasted no time in taking the lead leveling the aggregate scores after four minutes against Benfica. Pulisic flicked on a corner at the near post and Aubameyang, who had missed a penalty in the Estadio da Luz, arrived at the back post to power in a header. For the quarter of an hour that followed, Benfica reeled and it looked as though the game could be as good as done by halftime. But as in the first leg it hung on and began to establish a foothold in the game.

It couldn’t pull off the survival act for ever, though. Pulisic clipped in a second just before the hour and Aubameyang fired in Marcel Schmelzer’s cross two minutes later. The Gabon striker, looking suspiciously offside, ran on to Pulisic’s pass to complete his treble with three minutes to go and send Dortmund through.

As it stands, two Spanish teams and two German teams make up the quarterfinal field, with Barcelona, Real Madrid, Bayern Munich and Dortmund secure in the next round.